Digitizing oriented geologic strike/dip structural data

[Anonymous]

I want to digitize oriented strike/dips for bedding, fault and joint
structural information from maps into Autocad. Anyone have a process?

[Pointdump]

S,

"...digitize oriented strike/dips for bedding, fault and joint structural information from maps into Autocad"

I'm guessing that's something to do with earthquakes? How about a picture or a little more detail on what you'd like to do?

Dave

[Anonymous]

I would like to plot dip and strike data , this is basically the geological beds direction of dip and orientation of beds, for example if i find a structure thats on the surface of the earth that is showing on the surface, i want to plot the orientation of that structure so i can work out its orientation in the subsurface  for example  (look below) (Link) 

http://www.geologycafe.com/images/strike-n-dip.jpg 

So imagine this image as my 3d structure in a map, i would like plot its dip and strike and show it on the map as 3d image so that i can show its visibility .i.e. its orientation on the surface and subsurface allowing me to analyse the structure. what im planning on doing is using that criteria to show the orientation of a cone sheet ( a structure the shape of a cone created by geological process) within my map, i have data i.e. dip and strike ( orientation in degrees) for the cone sheet and i would like to project those data onto my map where these cone appears, plot the data and making a 3d cone in the process and then analysying it. 

The attached image (picture B) clearly illustrates the cone shape structure based on data that i want to kinda of replicate.

Thank you in advance.

[Pointdump]

S,

Whoa, that is some seriouly space-agey stuff you're doing! Way above my pay grade. I'm hoping someone familiar with dip and strike data will chime in.

Good luck to you.

Dave

[roskirko]

Here are some small peices of information that may help you.

Write a comma separated values (csv) file with the data such as:

Dip, DipAz, Strike, xs,   ys,  zs
15,  293,      23,    34, 18, 122 

where the meaning of the symbols are in the attached png.

Then use a scripting language like VBA or AutoLisp to write code to read the file.

Then write some code with elements like the following pseudocode to to calculate the end coordinates of the dip line coordinates. The scale is the length of the dip line you would want (the bigger the area, the larger the scale). dtr changes degrees to radians.

xend = xs + scale*cos(dtr(strike))*cos(dtr(dip))
yend = ys + scale*sin(dtr(strike))*cos((dtr(dip))
zend = zs - scale*sin(dtr(dip))

______________-

function dtr(angle)
angle/(180/3.14159)

____________

Finally add some code to draw a line from the coordinates for the dip lines. You can also write some code to draw the strike line.

[Anonymous]

Thank you very much I'll try this now

[roskirko]

Note:

The Dip Az is either 90 deg. or 270 deg different from the Strike Az.

I corrected a small error if found in the csv sample.

Dip, DipAz, Strike, xs,   ys,  zs
15,  293,      23,    34, 18, 122 

or

Dip, DipAz, Strike, xs,   ys,  zs
15,  113,      23,    34, 18, 122 

[Anonymous]

Cheers appreciate the help il give it a good go

[roskirko]

One more correction:

xend = xs + scale*sin(dtr(strike))*cos(dtr(dip))
yend = ys + scale*cos(dtr(strike))*cos((dtr(dip))
zend = zs - scale*sin(dtr(dip))